Re: Access GPT partitions on LVM volumes (map entry doesn't fit media)

[Brett Lymn <blymn%internode.on.net@localhost>]

On Sun, Jul 19, 2020 at 06:22:46PM +0200, Matthias Petermann wrote:
> 
> that sounded promising, but seems to only work with file-based volumes.
> 
> 	jupiter# vndconfig vnd0 /dev/mapper/rvg0-builder9
> 	vndconfig: /dev/rvnd0: VNDIOCSET: Operation not supported
> 
> Thanks anyway - I should take a closer look at LVM - I'm probably scratching
> the surface too much here. But it was worth a try.
> 

Well, if it is a device already you should be able to vgscan it to find
the logical volumes.  You may need to tweak the the device filters in
the lvm.conf to allow vgscan to look into /dev/mapper devices.  The
trickiest bit is if your volume groups in the vm are the same names as
the onese on the host but even that is not insurmountable.

I know this works - I managed to totally wreck a xen vm server with
guests by doing a yum erase -y for a bunch of rpms that had the kernel
as their dependency... oops.  After rescue booting the host and
reinstalling the xen kernel I mapped the guest volumes onto the host,
chrooted into the file system and installed the kernel rpm there.  These
vm's were using file based stores so I had to do the vndconfig (well
linuxy equivalent) but the process should be close to the same.  I was
able to recover all the vm's doing this.

-- 
Brett Lymn
--
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